(115) Repurposing Metformin Among Older Adults with Alzheimer's Disease and Other Dementias: Health Disparities and Equity Implications

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 446

Presenting Author(s)

Kevin Lu, PhD, BPharm, FISPE
– Associate Professor, USC College of Pharmacy, Columbia, South Carolina, United States

Co-Author(s)

Xiaomo Xiong
– University of South Carolina College of Pharmacy, West Columbia, South Carolina, United States
Minghui Li, PhD
– University of Tennessee Health Science Center, United States

Background: Alzheimer's and related dementia (ADRD) affects more than 5 million people in the U.S., but there is currently no cure for ADRD, and a few treatments to control symptoms. Repurposing drugs offers a route to therapeutic development that is shorter, inexpensive, and more likely to succeed. The literature documents that metformin may decrease the risk of ADRD although results are controversial.

Objectives: To assess the effects of metformin on the risk of Alzheimer’s disease and other dementias, and to determine if there are health disparities in the association.

Methods: We used the Medicare Current Beneficiary Survey, 2015-2017. Metformin was identified based on the generic name of metformin and the glucophage, glucophage XR, fortamet, glumetza, and riomet. Patients with ADRD were identified based on ICD-10 codes. Confounding factors included were year, age, gender, race, marital status, education attainment, rural-urban residence, census regions, household income, Charlson comorbidities index (CCI), body mass index (BMI), and health status. Multivariable logistic regressions were used to identify the impact of metformin on the risk of ADRD. All analyses were conducted using SAS 9.4.

Results: 33,590 individuals were included in this study. Overall, metformin is associated with a significant reduction of ADRD risks, and we found significant disparities in the association. Specifically, use of metformin among was associated with 34% less likelihood of developing ADRD for non-Hispanic whites (OR=0.66, 95% CI, 0.53-0.82), compared to non-Hispanic blacks (OR=1.52, 95% CI, 0.89-2.60), or Hispanics (OR=0.43, 95% CI, 0.18-1.00). Female gender and rural residents benefited more than their counterparts when using metformin (Female: OR=0.62, 95% CI, 0.44-0.87; Rural residents: OR=0.27, 95% CI, 0.10-0.75). The top five factors associated with the risk of ADRD were age, comorbidities, marital status, BMI, and race.

Conclusions: Our results suggest that repurposing metformin can help decrease the risk of ADRD, and the effect may be different among disadvantaged minorities. Inequity persists and disproportionately affects the underserved Blacks and rural minorities.